Asthma: key data sources

Primary care data

Practice Team Information (PTI)

The Practice Team Information (PTI) programme provides statistics on consultations in primary care in Scotland for a range of conditions including asthma. The sample is not sufficiently large to provide reliable prevalence estimates below national level. Data on asthma from PTI are reviewed in the primary care data page in this section. A general overview of the data provided by PTI is available from the Practice Team Information section in the ScotPHO site. The PTI  section on the ISD website provides further information and commentary on consultations for asthma.

Quality and Outcomes Framework (QOF)

The General Medical Services contract for general practices, introduced in 2004, includes a voluntary Quality and Outcomes Framework (QOF). The QOF measures achievement against a range of evidence-based indicators and includes quality indicators for asthma. The advantage of this data source is its national level of coverage; one important disadvantage is that only aggregated data are available, so that it is not possible to adjust for age or other differences when making comparisons between populations. QOF data on asthma are briefly reviewed in the primary care data page in this section. Detailed statistics on quality achievements and on prevalence of asthma in the QOF are available from the Quality and Outcomes Framework (QOF) section of the ISD website.

One important difference between asthma and COPD is reversibility. This indicates how much the airways obstruction can be reversed by bronchodilator drugs; in asthma there is usually much more reversibility than in COPD. Until April 2006, QOF definitions did not allow patients to be on both asthma and COPD registers - thus patients with a degree of reversible airways disease were not included on the COPD register. From 1st April 2006 patients with COPD and reversible airways obstruction were also included on the asthma register. As a result, comparisons in QOF-based prevalence before and after this time should be made with caution.

Prescribing data

Data on the quantity of asthma-related items prescribed by primary care services in Scotland are available from ISD's Prescribing Programme.

Secondary care data

Data on hospital inpatient and day case discharges for asthma are held in the Scottish Morbidity Record (SMR01) database. Data from SMR01 are presented in the secondary care data page in this section. An overview of SMR01 data is available on the ScotPHO site under hospital discharges. Data on outpatient consultations are held in the SMR00 database but these do not include complete information on diagnoses. While the specialty of the outpatient service used is recorded, patients with asthma may be seen in a number of different specialties (although mainly respiratory and general medical).

Mortality data

Mortality data by underlying cause of death (including asthma) are published annually by the National Records for Scotland (formerly the General Register Office for Scotland). Asthma mortality data are briefly reviewed in the mortality data page in this site. Detailed statistics for individual causes of death are published by NRS in the annual Vital Events Reference Tables, in Table 6.1 (Section 6).

Surveys and international comparisons

Scottish Health Survey

The Scottish Health Survey was carried out in 1995, 1998 and 2003 and then moved to a continuous design. The survey currently includes questions on doctor diagnosed asthma and self-reported wheeze. An overview of the Scottish Health Survey is available in the ScotPHO resources section. Detailed results are available from the Scottish Health Survey publications web page.

Global Asthma Network

Global Asthma Network was established in 2012 and has grown out of the International Study of Asthma and Allergies in Childhood (ISAAC) and the International Union Against Tuberculosis and Lung Disease (The Union). Global Asthma Network operates on the same principles used in ISAAC conducting surveys as resources allow. Global Asthma Network uses participants from centres around the world. In August 2014 there were 276 centres in 119 countries that had expressed an interest in participating in Global Asthma Network. The results of surveys and research studies are included in the Global Asthma Report 2014.